| 摘要 |
<P>PROBLEM TO BE SOLVED: To improve a total durability life by providing wear resistance of a worm wheel and restraining softening and swelling of a rubber damper in an electric power steering device having resin worm wheels and lubricated with grease. <P>SOLUTION: In this electric power steering device, a driven gear of a deceleration gear mechanism has a resin part which is made of a resin composition, and on the outer periphery of which gear teeth are formed. The deceleration gear mechanism is lubricated with a grease composition containing calcium sulfonate-calcium carbonate composite as thickening agent in amount of 5-50 mass% to the total mass of grease, and base oil in amount of 50-95 wt% to the total weight of grease. <P>COPYRIGHT: (C)2007,JPO&INPIT |
